The Puritan migration to New England was marked in its effects in the two decades from 1620 to 1640, after which it declined sharply for a while. The term Great Migration usually refers to the migration in this period of English settlers, primarily Puritans to Massachusetts and the warm islands of the West Indies, especially the sugar rich island of Barbados, 1630–40. They came in family groups (rather than as isolated individuals) and were motivated chiefly by a quest for freedom to practice their Puritan religion.[1]

After Charles I of England became king in 1625, this religious conflict worsened. Parliament increasingly opposed the King's authority. In 1629, Charles dissolved Parliament with no intention of summoning a new one, in an ill-fated attempt to neutralize his enemies there, who included numerous lay Puritans. With the religious and political climate so hostile and threatening, many Puritans decided to leave the country. Some of the migration was from the expatriate English communities in the Netherlands of nonconformists and Separatists who had set up churches there since the 1590s.

From 1630 through 1640 approximately 20,000 colonists came to New England.[3] The 'Great Migration' 1629–40 saw 80,000 people leave England, roughly 20,000 migrating to each of four destinations, Ireland, New England, the West Indies and the Netherlands. The immigrants to New England came from every English county except Westmorland, nearly half from Norfolk, Suffolk and Essex.[4] The distinction drawn is that the movement of colonists to New England was not predominantly male, but of families with some education, leading relatively prosperous lives.[1] Winthrop's noted words, a City upon a Hill, refer to a vision of a new society, not just economic opportunity.

Moore (2007) estimates that 7 to 11 percent of colonists returned to England after 1640, including about a third of the clergymen.[5]

The Puritans created a deeply religious, socially tight-knit, and politically innovative culture that is still present within the modern United States. They hoped this new land would serve as a "redeemer nation." They fled England and in America attempted to create a "nation of saints": an intensely religious, thoroughly righteous, community designed to be an example for all of Europe.